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A022473
Number of 2's in n-th term of A022470.
1
1, 1, 1, 1, 2, 3, 4, 5, 7, 7, 11, 14, 16, 22, 34, 37, 56, 70, 94, 113, 161, 191, 252, 341, 435, 568, 762, 973, 1276, 1661, 2169, 2817, 3657, 4811, 6200, 8178, 10603, 13878, 18015, 23582, 30617, 39919, 52100, 67898, 88298, 115624, 150200, 196145, 255716, 333151
OFFSET
1,5
LINKS
MATHEMATICA
p={-6, 11, -10, 17, -19, 14, -23, 16, -14, 17, -14, 19, -21, 29, -11, 2, -19, 18, -2, 7, -19, -18, 37, -16, 18, -19, 11, -10, -1, -25, 27, 12, 25, -22, -6, -22, 6, -9, 15, -12, 33, -3, -11, -3, -28, 24, 16, -7, 7, -19, 8, 4, -16, 0, -2, 18, 1, 1, -7, -2, 1, -2, -2, 3, 3, 1, -2, -3, 0, 2, 1, 0, -1}; q={-6, 9, -9, 18, -16, 11, -14, 8, -1, 5, -7, -2, -8, 14, 5, 5, -19, -3, 6, 7, 6, -16, 7, -8, 22, -17, 12, -7, -5, -7, 8, -4, 7, 9, -13, 4, 6, -14, 14, -19, 7, 13, -2, 4, -18, 0, 1, 4, 12, -8, 5, 0, -8, -1, -7, 8, 5, 2, -3, -3, 0, 0, 0, 0, 2, 1, 0, -3, -1, 1, 1, 1, -1}; gf=Fold[x #1+#2&, 0, p]/Fold[x #1+#2&, 0, q]; CoefficientList[Series[gf, {x, 0, 99}], x] (* Peter J. C. Moses, Jun 23 2013 *)
CROSSREFS
Sequence in context: A227972 A266620 A222415 * A214921 A265566 A265550
KEYWORD
nonn
STATUS
approved